Page 2 of 2 FirstFirst 12
Results 16 to 26 of 26

Thread: Large Format Compression Driver Listening Impressions

  1. #16
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    10,794
    Hi pos, I just re-read your thread from 2011.

    http://www.audioheritage.org/vbullet...50SL-vs-2452SL

    I find the subjective differences between the various drivers very interesting and quite maddening. As You point out, there are differences that we can't seem to quantify. Barry is working on getting his plane wave tube up an running. Maybe something will turn up there.


    Widget

  2. #17
    Senior Member 1audiohack's Avatar
    Join Date
    Jul 2007
    Location
    Las Vegas Nevada
    Posts
    2,931
    Hi All;

    Home for the holidays I am finally making some headway on the PWT and measurement platform front. A while back I bought a LarsonDavis lab grade high SPL mic (pr) and a 200V preamplifier rig. This kit is very nearly flat from 7Hz to 70kHz and below 1% distortion until you exceed 176dB.

    I discovered that most quality micís stated SPL limit is when they exceed 3% THD and in a PWT you reach 125dB at less than 0.3V. So even if the mic doesn't flatline on itís voltage supply, the distortion measurements mean nothing when the mic is likely far dirtier than the driver.

    My PWT test amp has always been a Techron 5507, functionally a well appointed D75. Usually I am just tickling it when testing comp drivers but today I found itís limit with a 2450SL, 166dB. I have better amps but I wanted to keep variables to a minimum while getting all the new stuff set up.

    The whole reason for all of this is to attempt to actually measure true linearity of these drivers from domestic levels to truly very loud. To see why I / we love some of them and not others.

    Getting truly calibrated has been a real pain and but I am gaining confidence in it now.

    I still have some work to do like integrate MNoise for a dense frequency test signal and swap in a more powerful amp thatís flat past 40k.

    I love time in the lab! Hopefully something of value will come from it.

    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  3. #18
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    10,794
    Very exciting. Keep it coming!


    Widget

  4. #19
    Senior Member pos's Avatar
    Join Date
    May 2007
    Location
    Paris, France
    Posts
    2,614
    Very exciting indeed!

    What about the distortion of the amp itself, for power tests?
    An autoformer could possibly solve the issue, or simply an lpad.
    Another solution would be to use a very quiet amp for low power tests, such as the new "hi power" headphone amplifiers (THX789 and the like).

    What mic are you using?

  5. #20
    Senior Member 1audiohack's Avatar
    Join Date
    Jul 2007
    Location
    Las Vegas Nevada
    Posts
    2,931
    Hello All;

    There are better amps here amps here and something else will make its way in if only for comparison. At some point everything in the chain becomes suspect. A very quiet amp would be of interest for sure. I will look into the one you suggest Thomas.

    The micís are the Larson-Davis 2530 on PRM902 pre amps.

    Looking at the pages of measurements in the transducer section on our site and everywhere else I could find them, JBL has used just about everyoneís measurement platforms over the years. I didnít see Audio Precision surprisingly but I only looked at comp drivers. There are several of them that were measured with TEF like the 2435Be and the 2452SL among others. Knowing what is shown in the text in the margins tells me exactly what the measurement set up was so that I can duplicate it exactly including smoothing and data points collected, very helpful.

    I ran a brand new 2450SL at 150dB and with ďHTRĒ which is TEFís harmonic tracking set at .5, 2nd and 3rd and the screen shot looks just like JBL,s. Within 2dB everywhere. I know thatís really pretty basic stuff but if this work doesnít line up with the majority of their shown data, the future data on linearity could easily be disregarded.

    By the way, anyone listened to M-Noise yet? I donít terribly mind pink noise, I just imagine I am at Niagara Falls and go about the work but M-Noise is like being behind a jet with you ears distorting, even at low levels itís just obnoxious.

    I think I will clean up the rack now that it all works and cycle a much cleaner amp in to see if that is yet visible in the data.

    All my best.
    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  6. #21
    Senior Member Champster's Avatar
    Join Date
    Apr 2014
    Location
    San Diego
    Posts
    297
    This is a very interesting discussion. Over the past 25 years, I've owned many large & small format CDs (JBL, Altec & TAD) & used OEM, Radian & TruExtent diaphragms. I can't remember any of them convincing my brain that I was hearing the original acoustic event as much as my M2s do. But then, I haven't heard Everests in a good environment (only at shows). So, I'd like to try that someday.

  7. #22
    Administrator Mr. Widget's Avatar
    Join Date
    Apr 2003
    Location
    San Francisco
    Posts
    10,794
    Quote Originally Posted by Champster View Post
    This is a very interesting discussion. Over the past 25 years, I've owned many large & small format CDs (JBL, Altec & TAD) & used OEM, Radian & TruExtent diaphragms. I can't remember any of them convincing my brain that I was hearing the original acoustic event as much as my M2s do. But then, I haven't heard Everests in a good environment (only at shows). So, I'd like to try that someday.
    Interesting...

    I have not been that impressed with the M2's D2 driver. I am not saying that I thought it was bad, but I prefer the sound I have heard from large TADs, 476Bes, and 476Mgs... am I fooling myself? Who ever knows?

    That said, I am very impressed by the 2216 in the M2s... some of the best controlled and most articulate bass I have heard.


    Widget

  8. #23
    Senior Member Champster's Avatar
    Join Date
    Apr 2014
    Location
    San Diego
    Posts
    297
    Quote Originally Posted by Mr. Widget View Post
    Interesting...

    I have not been that impressed with the M2's D2 driver. I am not saying that I thought it was bad, but I prefer the sound I have heard from large TADs, 476Bes, and 476Mgs... am I fooling myself? Who ever knows?

    That said, I am very impressed by the 2216 in the M2s... some of the best controlled and most articulate bass I have heard.


    Widget
    Hey Widget,
    Yeah isn't it funny, I've had all of those drivers as well and played with them at great length. They are all very good! Isn't it great that there are so many different successful speaker manufacturers around. We all listen for different cues and one flavor isn't everyones cup of tea. In fact, a lot (perhaps most) of the audiophile world hates horns of any kind. For them it is cones, electrostatic, ribbons, etc. To each his own. Trust YOUR ears.
    Paul

  9. #24
    Senior Member grumpy's Avatar
    Join Date
    Oct 2003
    Location
    SoCal
    Posts
    5,641
    Quote Originally Posted by 1audiohack View Post
    ...A very quiet amp would be of interest for sure. I will look into the one you suggest Thomas.
    Just noticed there's a slimmed down version in the works (sans balanced i/o) for a bit less:
    https://drop.com/buy/drop-thx-aaa-one-linear-amplifier

  10. #25
    Senior Member pos's Avatar
    Join Date
    May 2007
    Location
    Paris, France
    Posts
    2,614
    Quote Originally Posted by grumpy View Post
    Just noticed there's a slimmed down version in the works (sans balanced i/o) for a bit less:
    https://drop.com/buy/drop-thx-aaa-one-linear-amplifier
    There are some good candidates for both balanced and unbalanced operation now!
    For unbalanced operation the current champ is the topping L30: https://www.audiosciencereview.com/f...-review.15226/
    And you can also buy american: https://www.audiosciencereview.com/f...er-champ.9438/

  11. #26
    Administrator Robh3606's Avatar
    Join Date
    Apr 2003
    Location
    Rocinante
    Posts
    8,575
    Took long enough! Finally got the 2453SL's integrated into my HT mains. They sound really good! Glad I made the change.

    Rob
    "I could be arguing in my spare time"

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Array 880 Listening Impressions
    By Robh3606 in forum Lansing Product General Information
    Replies: 46
    Last Post: 02-07-2014, 08:36 PM
  2. Large format ?
    By richluvsound in forum Lansing Product Technical Help
    Replies: 6
    Last Post: 04-01-2011, 03:05 AM
  3. Large format alnico driver.
    By John in forum Lansing Product Technical Help
    Replies: 43
    Last Post: 03-06-2010, 12:58 AM
  4. Everest Listening Impressions
    By Don McRitchie in forum Lansing Product General Information
    Replies: 84
    Last Post: 01-12-2007, 05:14 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •